1. Field of the Invention
The present invention relates generally to caps for dispensing viscous liquids from flexible plastic containers. More particularly, the present invention relates to caps for dispensing viscous liquids without the accompaniment of lower viscosity liquid present in the container. Even more particularly, the present invention relates to caps for dispensing viscous liquids without lower viscosity liquid while simultaneously preventing accumulation of viscous liquids under the lid.
2. Description of the Prior Art
There are many different types of packaging for viscous liquids such as ketchup, mustard, shampoo, and body cream. It is common to use a plastic cap for dispensing viscous liquids from flexible plastic containers. Some caps have threaded inner walls so that they may be screwed onto the container. Other caps snap into the top of the container. These caps have single or multiple openings for dispensing the viscous liquid. Some have a recessed area around the opening on the underside of the lid. Others include a convex or concave projection to assist in dispensing the viscous liquid.
Two types of dispensing package for viscous liquids, as seen in U.S. Pat. Nos. 5,071,039 and 5,125,541, allow the user to dispense a measured quantity of viscous liquid. These packages are comprised of a reservoir for holding the viscous liquid inside the container, a channel for measuring the quantity of viscous liquid to be dispensed, a spout for the viscous liquid to exit the package, and an air trap to replenish the package with air. Viscous liquids are difficult to measure and pour. These packages are designed to alleviate this problem with an inexpensively produced package. They can, for example, measure and dispense a quantity of honey with sweetness equal to one teaspoon of sugar. These packages do not, however, address the problem of lower viscosity liquid discharge.
In another type of package for dispensing viscous liquids, there are recessed areas for collecting excess water and other debris to prevent contamination of the viscous liquid within the container, as shown in U.S. Pat. No. 5,411,182. The recesses are in the form of concentric rings extending from the center of the dispenser toward the outward edge. The outermost edge of the rings scrapes the sides of the container to prevent accumulation of the viscous liquid on the inside of the container. This invention was intended for use in dispensing viscous liquids intended for personal hygiene. It dispenses many small streams of viscous liquid from the holes in its surface rather than the single stream preferable for dispensing most types of viscous liquids. While the invention prevents lower viscosity liquid from entering the portion of the container holding the viscous liquid, it does not prevent its discharge from the container. This invention is only useful for dispensing a few types of viscous liquids, is expensive to produce, and does not address the problem of lower viscosity liquid discharge.
In yet another type of package for dispensing viscous liquid, there is an opening designed to minimize accumulation of viscous liquid adjacent to the outlet of the container, as shown, for example, in U.S. Pat. No. 6,041,975. The upper surface of the cap, including the outlet through which viscous liquid is dispensed, is recessed in a portion of the container. The container has a flexible portion that can be squeezed for dispensing the product through the outlet. The upper surface of the container around the outlet can be modified to minimize accumulation of the viscous liquid outside the outlet. This invention does not address the accumulation of viscous liquid under the surface of the cap that exacerbates the problem of lower viscosity liquid discharge.
The inventions cited have various advantages and disadvantages with regard to dispensing viscous liquids, but none fully address the problem of lower viscosity liquid discharge from viscous liquid containers. Furthermore, they do not offer a cost-effective solution to the problem of viscous liquid buildup that impedes dispensing. Therefore, what is needed is a method of dispensing viscous liquid that prevents discharge of lower viscosity liquid and is manufactured with minimal cost.
Among the objectives of the present invention are to provide a cap to dispense viscous liquids from plastic containers without the accompaniment of lower viscosity liquid. The cap is compatible with plastic containers typically used to package viscous liquids. Caps currently in use for dispensing viscous liquids do not prevent the discharge of lower viscosity liquid that may have built up in the attached container. Ketchup packaging is an excellent example. Condensation and settling, common in viscous condiments like ketchup, produces a lower viscosity, or watery, liquid that sits on top of the viscous condiment. When a consumer desires to use a condiment and turns the container upside-down to dispense the desired condiment, the lower viscosity liquid is typically discharged prior to the condiment. This problem occurs most frequently after the condiment is stored and then re-used.
Improvements to caps used for dispensing viscous liquids have failed to remedy the discharge of lower viscosity liquid. Some of these caps have a recess around the dispensing outlet which may initially prevent watery discharge, but whose usefulness is diminished after initial use of the product. The recess is designed to collect lower viscosity liquid when the container is inverted, allowing the viscous liquid to be dispensed while the lower viscosity liquid is held in the recess. When a container holding viscous liquid is inverted, however, the viscous liquid with greater density penetrates the lower viscosity liquid and clings to the underside of the cap. As the container is returned to an upright position, some viscous liquid may remain adhered to the underside of the lid while the lower viscosity liquid drains back to the top of the product in the container.
The product adhering to the underside of the cap eventually becomes more viscous and may dry and harden, filling the recess area. When the container is next inverted for use, there is no recess to collect the lower viscosity liquid as it has been filled with viscous liquid adhered to the cap. As a result, the lower viscosity liquid, which moves more quickly than the viscous liquid, precedes the desired viscous liquid as it is dispensed.
When used to dispense viscous liquids, caps with concentric outlets are especially vulnerable to adhesion and recess blocking problems. The adhesive property, i.e. surface tension, of viscous liquids enables them to cling to a particular surface against the force of gravity. The adhesive property of viscous liquids increases as the size of the surface they cling to is reduced. A concentric opening breaks up the surface of a cap, creating smaller surface areas that increase the possibility of viscous liquid accumulation. When the surface tension and adhesion of the viscous liquid accumulated under the cap is greater than the pull of gravity, it will remain in the cap recess. The retention of the viscous liquid in the cap recess prevents the collection of the lower viscosity liquid the recess was designed to retain. As a consequence, the lower viscosity liquid has nowhere else to go and is dispensed prior to the desired viscous liquid.
The present invention comprises a cap with an eccentrically located outlet on the top side of the cap and an elongated tube or channel extending at an angle from the inlet on the underside of the cap to the outlet. A unique aspect of the present invention is the distance between the inside of the cap wall or container wall where the cap is attached on a plane parallel to the underside of the cap and the outer edge of the inlet of the tube or channel is greater than 10 millimeters. In other words, the distance between the projection of the opening of the Inlet tube onto the plane of the underside of the cap and the furthest point on the cap edge, which will coincidentally place the projection of the outlet opening onto the same plane between the furthest point on the cap edge and the projection of the inlet onto the inside surface, will be more than 10 millimeters. By having the edge of the inlet more than 10 millimeters from the cap edge, the distance lowers surface tension and decreases adhesion of the viscous liquid. This distance reduces the occurrence of viscous liquid buildup on the underside of the cap.
The present invention is also unique where the elongated tube or channel is preferably set at an angle, or the outlet and inlet are spaced from each other creating an angle to the vertical, to minimize collection of undesired lower viscosity liquid in the tube or channel as the container is angled for dispensing the higher viscosity liquid such as ketchup, mustard and the like. The position and angle of the elongated tube or channel create a larger area on which to collect and disperse the lower viscosity liquid as the desired viscous liquid is dispensed.
The objects of the present invention are met by providing a cap designed to eliminate the problem of lower viscosity liquid discharge when dispensing viscous liquids. The cap may be affixed to a variety of flexible plastic containers commonly used in dispensing viscous liquids and is manufactured with a minimum of cost and materials. Further objects and advantages of this invention will be made apparent in the following description, references being made to the accompanying drawings illustrating the preferred embodiment of the invention.